Clinical implications of Epstein-Barr virus strain diversity

Abstract

The Epstein-Barr virus (EBV), a ubiquitous γ-herpesvirus, has been implicated in the etiology of several acute and chronic inflammatory, autoimmune, and malignant diseases. Although considered a genetically stable virus, recent sequence information obtained from a large number of viral isolates from around the world revealed that numerous viral variants exist. Whether these different strains differ in pathogenicity and immunogenicity and thereby contribute to the varying incidence rates of several EBV-associated diseases in different geographical regions is now studied intensively. The recent identification of amino acid sequence polymorphisms in a high percentage of all known virus-specific CD4+ and CD8+ T-cell epitopes, and of holes in the individual T-cell repertoire against epitopes derived from strain variants, may suggest that antiviral immunity is incompletely cross-protective against diverse EBV strains. These findings may have implications for immunological approaches seeking to prevent, monitor, or treat EBV-associated diseases.